Pneumatic elevator



Apnl 12, 1927. NH MITCHELL PNEUMATIC ELEVATOR Filed Sept. 2, 1921 F/c: J

} April 12, 1927.

A. H MITCHELL PNEUMATIC ELEVATOR F'iledSept. 2, 1921 2 shoots-sheet 2Patented Apr. 12, 1927.

ALFRED HILLYAR-D MITCHE HENRY ORMSBY BURGE, HENRY, SIMQN LIMITED, OFMANCHE Application filed September 2, 1921,

{GRANTED This invention relates to 'vators operating on principle andparticularly to extraction of grain or other 1,624,424 UNITED STATESPATENT OFFICE- LL, DECEASED, LATE OE PLUMSTEAD, ENGLAND; BY EXECUTOR, OFBRENTXVOOD, ENGLAND, ASSIGNOR TO STERI, ENGLAND.

PNEUMATIC ELEVATOR.

pneumatic elethe suction or vacuum devices for the material from thehopper of such elevators without the oted box or casing admission offree air thereto.

It has hitherto been usual this purpose either gravity or rotary wheelvalves. The

to employ for tipping air-locks former, that is to say, the tippingair-lock comprises a pivhaving two compartments With inlet openings atthe top which work in conjunction with a discharge opening in the hopperand with outlet openings at their lower part. from the hopper intoalternately and its weight ca to, tilt or capsize. As such The grain isdischarged the two compartments uses the device a tipper which isover-balanced by the weight of the grain or the like'being discharged,

must be large enough to tip with the lightest class of grain, namelyoats, it is obvious that when the same device is employed fordlscharging wheat, which is one and a half times heavier than oats,

it will capsize when little more than half full, so that a considerablewastage of air is the result.

A further disadvantage of this type of discharge device is that, as

it must be sufficiently free gravity, it is to capsize by not possibleto make a perfectly tight joint between it and the face of the hopper,under which it there is alwaysa certain age at this partworks, so thatamount of air leak- The tipper air-lock, however, possesses theadvantage that as it has a deep receptacle of some size, large pleces offoreign matter, of which siderable amount in grain, can

there is a conpass into the same with only slight possibility of causinga stoppage.

In the case of the rotary wheel-valve, un-

less this is made abnormally large, the receiving pockets with which itis provided are comparatively small, so that any substance of quitesmall dimensions,

a nail or a piece of wood or may fall on to thettop of the foreign suchas sacking, which grain or other material in the pocket when the latteris practically full, usually gets nipped between the knife edges formedby the divisions in the wheel-valve and the sliding faces in which itworks, the result bei ng that the apaccompanying Serial No. 498,071, andin Great Britain November 20, 1913.

UNDER THE rnovisrons or rm: Aer crimson s, 1921, 4i STAT. L, 1313.

paratus is put out of action. These wheelvalves, however, are alwaysdriven by power and the working faces, therefore, can be kept incontact. sufficiently tight to make a good joint.

The present invention has for its object faces of the tipper and hoppercan make a sufliciently' tight fit to prevent any wastage of air at thatpart.

In a suitable arrangement for carrying out the invention the tippercomprises a box having two compartments provided with a valve face atits upper part having'inlets for the grain or other material anddesigned to move in contact with the valve face provided at the bottomof the hopper; the lower part ofeach compartment is provided with avalve or door, the'face against which the said valve bears being soinclined that the valve or door of the rip-coming compartment is alwaysquite closed before that compartment is opened to the hopper, thuspreventing any possible 'in-rush of free air into the vacuum chamber, afailing which is common to existin types of tipping devices. The tipperis designed to be positively reciprocated by means of a connecting rodactuated by a crank which is rotated at a suitable speed by any suitablegear.

In practice the connecting rod may be of an elastic nature so as toyield, should the apparatus become clogged, thereby preventing breakage.

To enable the invention to be fully understood, will be described byreference to the drawing, in which Figure 1 is a sectional side view ofa tipping airlock constructed according to the invention, Figure 2 is asectional view at right angles to Figure 1, Figure 3 is a view of a'detail hereinafter described," Figure 4: is a similar view to llipau'o lo'l, a, modified construction, and Figure 5 is a plan of a detailthereof.

(1 represents the hopper of the grain or other pneumatic elevator and Z)is the tipping box which is pivoted at c and is divided into com'iartments' (Z and e by means of the partition f. The upper part of thetipping box is provided with the valve face 9 having inletopenings 72for the grain. This valve face 9 moves against the correspondinglyshaped face j upon the bottom of the hopper a. Each of thecon'ipartments (l and c is provided at its bottom with an outlet in forthe grain or other material, having a :iace Z against which bears thetreoly suspended valve or door we, the inclination of the face Z beingsuch that the door or of the compartment to which it is attached,completely closes against the said face Z on the upward moven'icnt ofthat compartment before its inlet it passes beneath the usual airexhaust port or by ass a thus preventing any possibility of i rec airpassing into the acuum chamber through the tipping box.

a the connecting rod which connected to the tipping-box 7) at the pointit below the pivot c, and 0 is the crank by means of which the saidconnecting rod is moved baclm'ards and forwards so as to positively tiltthe tipping box alternately in opposite directions, The crank o iscontinuously rotated by means of the worm gear 1 which is driven by thebevel gear (1 actuated in any suitable way.

The connecting rod n is preferably, as shown in section in Figure 3 madeof an elastic nature for the purpose above do scribed. For this purpose,it is divided into twoyparts one of which carries the sleeve 1* in whichslides a piston s on the end of the other portion, springs 2 beingfitted in the sleeve 7* upon either side of the piston s These springs tare of sutlicicnt strength to move the tippcr over from one position toanother without any appreciable compression or expansion taking placcaslong as the tipper can move under normal conditions. In the event of anyforeign substance, how ever, becoming jammed in the apparatus, the sprngs are of suliicient length to be compressed or expanded as the casemay be, to a sufficient extent to enable the crank to complete itsrevolution, thus obviating any illjury to the ap iiaratus. as the jammedmate rial can fall clear into the upcoming tipper on the return strokeof the latter.

As will, be obvious the crank and connecting rod gear used forreciprocating the tippiug-box provides a motion in which there is aslight dwell or period of rest at theends of the strokes orreciprocations, and this rest is what is in practice required. If,however, it is desired to lengthen this period the connecting rod 11 maybe slotted as shown at if, thus providing for a certain amount ol. lostmotion and com-implant, increase of the terminal period or rcst.

in the modified construction illustrated in Figs, at and 5 theconnecting rod n is attachtul to a cross-head w where'lroin side rods 4)ox-- tend freely through sleeves .1: on a cross rod 1 which is pivotallymounted in lugs on the lIlIJPiDg-lJOX Z). Springs 2 are mounted on theside rods *1) at either side of the cross rod 3 and bear against thesleeves (a and stops 3 on the rods 1: to term a resilient connectionbetween the side rods v andthc cross rod 3 and allow 01" relativemovement between the tipping box and the connecting rod n in case ol thebox januniinr. The crank pin 0 which dri "cs thoconnecting rod a isprovided on a disc l which is rotated by appropriate gearing 5.

1n the gravitation type of tipper as. hitherto used, strong butters haveto be made use of for absorl'iing shock on each drop of the tipping-boxand the whole apparatus has to be made of considerable strength towithstalul these shocks. The necessity of employing butlers is obviatedby this invention since under the positive mechanical actuation oil thetipper, the latter tilts without shock. Moreover, the reserve of spacewhich is required in gravitation tippers as hitherto made for thereasons above specified is no longer-necessary in the improvedapparatus, which can, therefore, be made of less capacity than, hashitherto been necessary, whereby unnecessary wastage of air is obviated.

That is claimed as the invention and desired to be secured by LettersPatent is 1. lhe combination with,: themouth of a grain hopper, of anareuate valve seat formed at said mouth and provided with an exhaustport, a tipper provided with an arenate upper end fittingsaid seatandhaving spaced inlet ports, said tippcr being divided into a pair ofcompartments into which said inlet ports respectively open, each of saidcompartments having a valve at its lower end, and mechanical meansconnected to the tippcr for oscillating it at a definite rate regardlessof the kind of grain being handled to bring each inlet port alternatelyinto registration with the mouth and exhaust port and then out ot' suchregistration and permitting intervals of rest of said tipper betweenmovnnents.

2. The con'ilgiination with the mouth of a grain hopper, of an. arcuatevalve seat formed at said mouth and provided with an exhaust port, atipperinovided with an arcuate upper end fitting said seat and havingspaced inlet ports, said tipper being divided into a pair ofcompartments into which said inlet ports respectively open, each of saidcompartments having a valve at its lower end, and mechanical means toelfect oscillation of said tipper to bring each inlet port alternatelyinto registration with the mouth and exhaust port and then out of suchregistration, and including a rotating crank and a yieldable linkconnecting said crank and tipper. a

3. The combination with the mouth of a grain hopper, of an arcuate valveseat formed at said exhaust port, a tipper provided with an arcuateupper end fitting said seat and having spaced inlet ports, said tipperbeing divided into a pair of compartments into which said inlet portsrespectively open, each of said compartments having a valve at its lowerend, and mechanical means to effect oscillation of said tipper to bringeach inlet port alternately into registration with the mouth and exhaustport and then out of such registration, and including a crank and a linkconnecting the crank and tipper, the connection at one end of the linkbeing a pin and slot connection whereby to permit rest of the tipperbetween successive movements.

4. The combination with the mouth of a grain hopper, of an arcuate Valveseat mouth and provided with an formed at said mouth and provided withan exhaust port, a tipper provided with an artration, and including acrank and a link connectilg the crank and tipper, the connection at oneend of the link being a pin and slot connection whereby to permit restof the tipper between successive movements, said link consisting ofsections longitudinally movable with respect to each other and havingspring means yieldingly holding said sections in normal relation.

In witness whereof I have hereunto set my hand,

HENRY ORMSBY BURGE, Emecutglr of Alfred Hz'ZZg ard Mitchell, de-

cease

